1. Field of the Invention
This invention relates to a ring joint for connecting an inner webbing and an outer webbing to each other in a seatbelt system for protecting an occupant in a vehicular emergency.
2. Description of the Prior Art
Ring joints have been used in seatbelt systems having an outer webbing and an inner webbing and so arranged that a ring joint base is secured to the forward end portion of the inner webbing, and the intermediate portion of the outer webbing is partially wound around this base.
With this ring joint, the occupant can change the length of the lap restraining portion and the length of the shoulder restraining portion of the outer webbing, making an accommodation therebetween when the webbings are to be fastened about him, so that he can be brought into the optimum webbing fastened state when occupants of different physical builds enter the vehicle or when an occupant changes his driving posture during driving. However, in the seatbelt system using the ring joint as described above, when a deflected load acts on the webbings in a vehicular emergency, a contact portion of the outer webbing, and also a contact portion of the inner webbing may move in the widthwise directions of the webbings in the ring joint, thereby possibly causing shifting of the webbings.
When the webbing or webbings shift in the widthwise directions, the shift may cause decreased tensile strength in the longitudinal direction of the webbing or webbings.